Sealing and thrust balancing means for rotary compressors and analogous machines



I wow- NCING M AN EA-LING AND rnnus'r-BA Elms ron ROTARY g I l .ICOMPRESSORS- AND; mesons MACHINES 4 ,23, 1925 r 2 Sh.

1 Filed Nov driven/5K5.

v SEALING AND THRUST BALANCING MEANS FOR ROTARY 1mm; 31.- Emma E 1559293 COMPRESSORS AND ANALOGOUS MACHINES Filed Nov. 23,1923 2 Shoots-Shut .2

Patented Jan. 20, 1931 nnxsr won, or :LEIIPSIG, summit, aassmnon TocAimma nucmmanme con-2 r J POBAAIPIOIN', OIF NEWARK, NEWJEBSEY' ammo m mnuswm mcmamms iron may coxrms'ons, 11in) g QANALOGOUSIACHINEBJ P Q hpplication-flled November 23, 1928:, Serial No. 6 7 6,87,1 and in Germany- Awh le, 1 923. v. l:

This invention relates to means for. use.

with'rotary gas compressors, vacuum pumps and analogous machines for balancing the end thrust on the rotor shaft of the machine I; 3 and relieving the consequent: friction-{and for providing a substantially frictionless gas-tight seal or closure for'the' opening through which the rotor shaft passes-outlet. the compressor casing fol-connection with a driving motor or other device. More ,pa r; ticularlyf-my invention relates to improvements in a mechanism fora similarpurpose disclosed in United States Letters Patent" No; 1,575,970 to Willis HQCar'rierQfWh'ile the invention is specially desirable foru'se'on the centrifugal exhausters "or *compressors of refrigeratingjapparatus, it is not restricted to such use but isapplicable to elastic fluid compressors and analogous machines for other purposes in which'it is im portaiit to reduce the friction to the minitheleakage of air or gas therethrough, bothi when the machine is-and is not inzoperation. One'object of the invention is toprovi'de'" I an fefiicient and practical fiuid' pressure means of novel construction for balancing or taking theendthrust of the'rotor shaft of themachine and for eliminating the 'fric tion which wouldbe'incidentto-tlie use of-a thrust bearing in which there ismet al to; metal contact. Another object is to provide an efficient and reliable closure device of novel construction for the shaft'opening' of 3' the machine comprising'a substant ally frictionless'liquid sealwhich prevents theleakage of air or gasthiough the shaft opening when the machine is running, and a'valve or element which automatically closes theshaft opening against the passage therethro'u'gh of air or gas when the machine'is not running. Still another object is' to provide a single device which" performs the triple function "of a thrust balancing device, a valve for closing the shaft opening when the machine is not running 'anda liquid seal for: the shaft:

opening when the machine 'runningz A further object'of the invention'is'to simplify and improve" thrust balancing and sealing mechanisms of the sort mentioned in the forth in the claims.

invention.

other respects hereinafter on lines 2-2 and 3+3, Fig, 4, .res})ectively. Fig. 4 is an enlarged longitudinalsection;

a1 elevation of a portionof the compressor showing the liquid sealing and thrust bah "anc ngm'eans v j n represents the enclosing casing orhous; ing of thecompressor. This inventionfis not concerned with the CdIlStI llCtlOn-Qfitheqcbme pressor proper and this maybe eriknown or suitable construction, thejdra wingsindicat, I

mg inFlg. 1 the exteriorgofa ,inultiplestage I compressor having aplurality of. rotaryfim- .ipellers', the last ofj'which tat the compression. mum and to sealthe shaftopening against .end of the machine, delivers "into a} discharge j chamber C represents the rotor. shaft of r the machine." This shaft isjjournalled in I "suitable;bearings'at,op osite endsjfof fthe compressor casing. JD; I

' i fg he S The bearingfor the opp ipeiid of the shaft;

is O hGWn' butis inclosed\v itliinfth e por- 4' ,tion ofthe casing" designnte len'iimFi i1.

One end'ofithe'shaftC, the right hand endi there'ofias illustratedin'the drawings, ex tends out of the compressor casing for con v 'nection wi'tha driving turbine or other motor or device, The other end of the shaft C iscompletelyhoused or. enclosed the compresso'rcasin'g so: thatit is only necessary a. to provide a s nglefsealing or :fclosurefdevioe' forthat end of the shaft which. e2tends out I of the casing.

The compressor is of a design. suchfthat it s I produces an. end'thrust on thesha'ft C mane; 1

direction, that isin a left-hand, direction as? I shownjin Figs l and 4, ndfftlielshaft: i mounted so that it is adapted t'olhavela slight if endwise movement [its bearings. "Ihis' thrust is; balanced or resisted; and prevented' from causing friction by the following means:

'10 represents a'combined thrust balancing and sealing member or collar, hereinafter 751 indlcatesthe A called the sealing member, which surrounds and is fixedly secured or formed on the shaft.

As shown in the drawings, this member is stationarily secured on the shaft between a shoulder 11 on the shaft and a coupling member 12 secured on the outer end of the shaft. Thelsealing memberlO faces a. stationary, annular member or part 13. of the compressor casing, which acts "as a stop to limit the-movementof the shaft to' the left, due to the end thrustthereon, and forms the inner endof an annular sealing chamber'14 which "surrounds the shaft-C and 7 into which the sealing member 10*projects' and is adapted to rotate. Preferably the stop member 13 is formed by' a separate sleeve or bushing which surrounds the shaft and is stationarily secured inan'opening orseat 15 in the end of the compressor casing by a sep- 'b er 14 is form arate cylinder'orpart 16 which surrounds the shaft G and fits in anannular seat 17 in the 'end'of the com res'sor casing and engages; the

outer end of't i'e bushing 13. This cylinder 16, in turn, is secured in its seat 17 by an' end piece 18 which is suitably secured, for instance by'bolts 20,"on the end ofthe compressor casing and has an opening 11811 through which the shaft'O extends'out of, the compressor casing. This end piece 1s provided witha circular-rib 19 which engages the peripheral portion of the cylinder 16 so that whenthe securing bolts 20 forthe end" piece'18are tightened, the end piece will force the cylinder 16 tightly into its seat 1 7,and the cylinder 16, which engages the outer end of I the bushing 13, will orce the latter tightly into place in "its seat l5andjsecillrejit. 1A aS-I tight joint is formedbet-ween'the endplece 18'and, the cylinder 16 and end of the casing so that there can not be anvleakage around the cylinder. "As shown, the sealing champlied under pressure tei the sealingchamber 14,.as hereinafter explained, through passages leading to the end face of the stop b'ush i'ng 13,the oil being adaptedjto escape between theend face of the bushing and the face lofthe sealing member into on the shaft, thereby balancing'or yieldingly resisting said end-thrust." This oil pressure is ancient toihold th s lin m m 1 slightly awayf rom' the opposing stop member13so that the oilth'usforms aJiquid. cushion fwhich prevents actual contact hee ed byan annular recess in t he inner end ofthefeylinder I v Liquid preferably lubricating oil, is super 14, the following construction is prefer-,- "ably employed:.. 30 represents a reservoir tween the metal parts 10 and 13 and revents afiipreciable friction due to the end t rust on t e shaft.

The cylinder or part 16 before mentioned, which is annular and surrounds the shaft 0, is provided withconcentric outer and inner cylindrical flanges 21 and 22 which prefera ly extend in opposite directions, the former outwardly and the latter inwardly parallel with the shafti23v-indicates anannular piston arranged! to? slide len hwise in the cylinder formed by the outer ange 21. This piston Has atubularhub-portion 24, surroundmg th'e'shaft C, which slidably fits in the hollow inner flange 22 of the c linder, and the hub 24 is provided with a anged or broad inner end 25 whichis disposed opposite and adjacent to the outer face of the sealing memher 10. A suitable spring' 26acts on the pis ton 23, tending to move it inwardly and cause the inner end of .itshub to contact withthe sealingmemberlO. .The spring 26 may be of any suitable type but, preferablyconsistsgof a spring plate secured'to the outer end of the pistonand having radial arms 27 i which are, seated, in aninternal circular roove 28 inthe outer portion ofthecy inder flange 21, the piston thus bein retained in the cylinder bythe spring. llie spring can be iny serted-into place in the} groove 28 simply by moving the spring arms.inwardlythrough slots 29 in the end of the flange 21 connecting, with the, roove 28, andthen turningthe" Duringv the operation of}, the machine the 1 liquid for sealing oil is also, delivered under f springuntll the arms engage in the groove 28.

pressure to the cylinder 16 and acts to move- ,the pistonoutwardly against the action of the spring 26so asto holdthe end 25 otthe piston hub slightly out of contact withthe:

sealin member 10; In the normal opera--.

'tion 0 the device, the clearances betweenthe. sealing member 10 andthe stop member 13,

and between the sealingmember-and the end 25 of the piston hub, are very sli ht, sonly suf- .ificient to permit the passage o the sealing, liquid: through the spaces -betweenthese; v

parts. i i

re'ssure'tothe cylinder 16 and sealing chaminto which the oilor sealing liquid-is deliv- For thepurposeofsupplying the oil under I ered by asuitable pump which operates when;

the compressor is runningi so as to maintain a the hquld under pressure 1n the IGSGIVOII;

whenever the compressor is in operation.v I

leading from the lowerportion of the 1011 res-- ervoir and connecting by anannular chamber32 and, one-ormore' ports 32a in the stop innerportionthereof onnear the s aft C.

a The'oil is delivered fromthis reservoir to the sealing chamber 14throu ha passage 31 bushing 13,.With an annular groove 33 in the l rend face 'of thebushing 13, preferably-atthe The upper portion of the oil reservoir 30. is also'connect'edwith the sealingchamber 14 by a second passage '34, a second chamber 35 in thebushin'g'13, and one or more'zports' 35d'to the outer end of the-bushing, these orts 35a'being preferably disposed'further romthe center of the sha'ftthanthe groove 33. "The passage34 preferably has anKup ward extension or'standpipe 36 extending up into the oil reservoir and the oil can enter the passage 34 only when the oil rises 1n the reservoir to the open upperlend of the'stand pipe 36. "The passage 34 also connects by one or more orts 37 with the cylinder 16 to deliver the 011 to the cylinder toroperatmg :1 the piston 23; When the compressor'is run-' ning the" oil is delivered tothe reservoir 30 through an inlet 38, Fig. 4, and is maintained under sufiicient' pressure in the reservoirto compress the air in the reservoir above the oil and permit the oil to-risehigh enough to enter the standpipe and dischargethrough f the passage 34. When the'com' ressor is not running, the oil is not delivere to the reser-.

voir, so that the pressuretherein is relieved' and when the oil lowers therein toja level low the top of the standpipe, thenkthe 011 can discharge from "the reservoir only through the lower passage 31'. While the compressor is in operation, therefore, the Oll under pressure operating on the piston 23 U will move the latter outwardly against the,

action of the spring 26; and hold the inner end 25 of the'piston hublout of contact with the sealing member 10. Also the pressure of the oil or liquid from theores'ervoir through the passage 31' and the ports 32a will act against the inner faceof'the sealing member 10 and hold the latter but of contact with the opposing 'face' of the stop bushing '13 1n opposition tothe end-thrust on theshaft.

Theoil under pressurewill also passffrom the passagef-M; through the ports 35a tothe space between the sealing member and jthe opposing stop member. 7 Thus the oil is delivered tothe sealing chamber 14 and the rotation of the sealing member inthe chamber acts centrifugally to retain a bqdy'ofgoil in the outer portion of this-chamber around i the outer edge of the. sealing member, thereby forming. an efiective liquid seal which prevents the leakage of air orgas'pastfthe same into or out of the compressor casing When thecompressor stopsor 18 not running the pressure in; the reservoir 30 will be reliev'ed, as above explained, andlih will lieve the pressure in the upper-passage 34; and the cylinder 16 andthe piston 23 will then be moved' inwardly by its spring 26 until the end 25 ofthe piston-hub engagesthe sealing member and moves the, shaft inward- 1v until arrested by the engagement 'of the ,sealingl member withthe outer face oi the stop bushing 13.1 The sealing member then acts as a valve seating againstthe stop mem ber 13 to reventthe passalgeof air'or gas between t esejb'parts. t istiine the oil will be delivers under a sli lithead orpres sure, due 'to tli'e'elevation" o the oil reservoir 30; through the ports 32a to the outer'face of the stop memberand is adaptedto seep through between the latter andjthe sealing member; thereby maintaining 'an'oil film, be-" tween these parts which sup lements the seating of the valve in efiectual y closing the f j' pe g and-prev nting theleakage of I" I air or gas therethrou'gh when the compressor 7 stop bushing .13 oppositethe sealing member'10an'd surrounding the'port's- 32a and 35a. oil eollects in succession of con centrlc rlngsf'in thegr'ooves 39 which further' increase the eficiencyiofitheseal;

The machinefis provided with an" oil cir culating ipump *off'any: suitable kind, indi-- cated 1e40, Fig. 1, whlch, when ftlleicompressor is runningy is adapted todraw'th'e oil froman oiltankl toiwhich theoil can flow from the sealing chamber '14 through a 'suitabletrap (not sl1own)"and the pump '40 def livers the oil through a discharge pipe 42to the inlet-380i the .oi is operatively connected with the compressor or is otherwise'driven solth'atit acts to always maintainthe oil under pressure in the reservoir 30 while the compressoris in operation. The pump 40 is also used to deliver oil to the shaft bearin s, the oil inlet for the bearing D being shown at 43,' Fig'.. 4;

r'cfesiervoir. The oil pump In order to prevent the oil or sealing liqu'idwhich discharges fromthe sealing-chamber member is preferably provided at'its vouter 14 from escaping through the'shaft opening is 18a and beinglost, the hub of the sealing end portion with a series of peripheral; ,oil-,

throwing edges'lor ridges 44 whichfare' adapted to throw the oil onto a plurality of closely spaced plates 45 which are secured in the end piece 18 andstraddle the upperpor tion of the hub of the sealing member. These plates are substantially semi-circular in form, extending'around only the upper half. orportion of the hub offthe sealing "member and the oil which is thrown onto the same from the ridges 44 runs downand'fdripsoff of the oppositeends of the plates 45 into the hollow 'end piece 18, from'whi'c'h it flows througha return passage 46 to the trap ehamber47 leadmg to the [collecting tank llg'from which th e 7' oil: pump" returns the oil; to the reservoir 48 in'dicates'ordinary oil arresting rings jsur-l ferred toin the claims.

rounding the shaft in theshaft'opening 18a. I A similar oil arrester49 is preferably provided at the inner end of the-shaft bearing D for preventingthe oil from escaping'along Lthe shaft'into the compressor casing." I

As a further safeguard toprevent the oil ing chamber having a face which cooperates.

with a sealingmember. By the use of the word chamber Ifintend to mean a struc- 5 turehaving an enclosed space or compartmentwith a :wall of the compartment or space corresponding to the face of thejchamber re Iclaim as n invention; 1 a

1. Tlie com )ination with a fluid compressor o'r analogous machine having a rotary shaft extending through an opening in the machine casing, of a liquid sealing means for preventing leakage of gas through said shaft opening'comprising an annular sealingchanu ber surrounding said shaft; an annu1arsea1- ing member on said shaft arranged to rotate I In said sealing chamber, saidchamber and member having opposed normally contacting faces, means which operate While the machine is running to deliver liquid under pressure between said opposed faces whereby the ated by said pressure liquid which holds said automatic means from its said action while the machine is runn ng. a 2. The combination with a fluidcompressor or analogousmachinehaving a rotary shaft extendingthrougl'i an opening'in the machine casing and constructed to produce rection, of a liquid sealing means for preventing leakage of gas throughsaid opening comprising an annular sealing chamber. surrounding said shaft, an annular sealing member fixed on said shaft to rotate in said sealing chamber, said sealing chamber and sealing member having adjacent opposed faces so disposed that the endthrust on said shaft, tends tomove them into contact, and means whichop'erates while the machineis running to deliver liquid under pressure betweensaid opposing faces whereby the liquid acts on said sealing member to hold said opposing faces out of contact'in opposition to said end thrust andxforms a liquid seal between said opposingfaces to seal'said shaft opening.

3. The combination with a fluid compressor or analogous machine having a rotaryshaft. extending through an opening in the machine l casing,'of a liquid sealing means for prevent- Y ing leakage of gas through said openingcom- I'iSlIl" anannu'lar sealin chamber surroundingis aid shaft, an annular sealing member fixed on said shaft to rotate'in said sealing chamber, said sealing fchamber, and sealing v member having adjacent opposed faces which the endthrust on said shafttends to move into'contact, means which operates while the machine is running to deliver liquid under pressure between said opposing faces where by the liquid acts on said sealing member to hold'said'opposing faces out of contactv inn opposition to said end thrust and forms a v liquid seal between said opposing faces to seal said shaft opening, .an operating device Whichactson said shaft to move'said op w posing faces into contact and form a,-closure for said shaft opening when the rotation of said shaftstopgand additional means actuated by said pressure liquid which hold'ssaid operatingdevice from its said action while the machine is running. p a

4. The combination witha flu d compressoror analogous machinethaving a rotary shaft extending'throughflan opening in the machine casing, of aliquid sealing means for preventing leakage-of gas through said opening comprising an annular sealing chamber surrounding said'shaft, an annula-r sealing member fixed on said shaft to rotate in said seal ng chamber, said sealing chamber and sealing member having adjacent opposed faces which the endthrust on said shaft tends to move into contact, means which operates a while the-machine 18 running to deliver liquid under pressure between'jsaid opposing faces whereby the liquid acts on said sealing member to holdsaid opposingfaces out of contact in opposition to said end thrust and forms a liquid sealbetween said opposing faces to seal said shaft opening. and an automatic de- .vic'e Which'acts to move said opposing faces into contact and form a closure for said shaft I opening when the rotation of the shaft Ptops, end thrust on said shaft axially infone disaid liquid pressure acting on said device and preventing said automatic action there- .of when said machine is running. v 5. The combination'with a fluid compres sor or analogous machine havinga rotary shaft extending through an opening in the machine casing, of a liquid sealing means for I preventing V leakage of gas through said I opening comprising an annular sealing chamber surroundingsaid shaft, an annular sealwhich the end thrust on said shaft tends to lmi move into contact, means which operates while the machine is running to deliver liquid under pressure between said opposing faces whereby the liquid acts on'said sealing member to hold said opposing faces out of con tact in opposition to said end thrust and forms a liquid seal between said opposing faces to seal said shaft opening, a springactuated operating device which acts to move said opposin faces into contact when the r0,-

tation of sai shaft stops,and means for de- I livering liquid under .pressure to said operating device when themachine is running to oppose the movement of'the same by its spring.

6. The combination with a fluid compressor or analogous machine having a rotary shaft extending through an openIngin the machine casing, of a liquid sealing means for preventing leakage of gas through said opening comprising an annular sealing chamber surrounding said shaft, an annular sealing member fixed on said shaft to rotate in said sealing chamber, said sealing chamber and sealing member having adjacent op-.z posed faces which the end thrust on said shaft tends to move into contact, means which operates 'while the machine is running to deliver liquid under pressure between said opposing faces whereby the li uid acts on said sealing member to hold sai opposing facesv out of contact in opposition to said end thrust and forms a liquid seal between said opposing faces to seal said shaft opening, a piston, a spring which acts on said piston to move said opposin faces into contact when the rotation of said s aft stops,and means for causing liquid pressure on said piston to hold the same against action by said spring when the machine 1s runnmg.

'to move into contact, means which operates while the machine isrunning to deliver liquid under' pressure bet-ween said opposing faces whereby the liquid acts on said sealing mem her to hold said opposing faces out of contact in opposition to said end thrust and forms a liquid seal between said opposing faces to seal said shaft opening, a piston having a portion arranged at and adapted to contact with the side of said sealing member op osite that on which said liquid acts, "means or delivering liquid under pressure to said piston to hold said portion thereof out of contact with said sealing member when said machine isv running, and means for, moving said sealing member toward said opposing face of said 1 sealing chamber when'the rotation of said shaft stops,

8. The combination with afluid compressor or analogous machine having a rotary shaft extending through an opening in the machine casing andwhich causes end thrust in one direction on said shaft, of an annular member fixed on said shaft, an annular stop member surrounding said shaft adjacent said first annular member, said annular members having opposed faces adapted to contact to limit the movement of said shaft by said end thrust, a cylinder surroundingsaid shaft, a piston movable in said cylinder and having a portion arranged to engage said annularmember for moving the same toward said stop member, a spring acting on said piston for so moving said annular member, and means for delivering liquid under pressure to said cylinder and between said opposing faces when said machine is running to hold said faces out of contact in opposition to said end thrust and to hold said piston out of contact with said annular member said spring.'

9. The combination with a fluid compressor or analogous machine having a rotary shaft extending through an openin in the machine casing, of means for dedivering liquid under pressure to form a liquid seal for said shaft opening, and an arrester for said sealing liquid between said sealing chamber and said shaft opening, said liquid arrester comprising liquid-throwing edges on said shaft, and a plurality of spaced plates partially only surrounding said shaft opposite said liquid-throwing edges and constructed to catch the liquid thrown off from said eldgps and divert the same away from said s a t.

in opposition to 10. The combination with a fluid compressor or analogous machine having a rotary shaft extending through an opening in the machine casin of a liquid sealing means for preventing lea (age of gas through said opening comprisinga'bushing surrounding said shaft, a-cylinder surrounding said shaft adjacent said bushing, means for securing said bushing and cylinder stationarily in said 'cassaid cyllnder andbushlng forming an ing, annular sealing chamber around said shaft,

an annular sealing member fixed on said shaft to rotate in said sealing chamber, a piston auovable in said cylinder and having a portion adaptedto engage said sealing member, means which operates wlnle the machine is running to deliver liquid under pressure to vsaid sea-ling'cha-mber and cylinder to hold said sealing member out of contact with said bushing and said piston, and means for actuating said piston'to move said sealing memher into contact with said bushing when the a rotation of said shaft stops.

ERNST WOLF; 

